Chimeric antigen receptors, compositions, and methods

ABSTRACT

This disclosure describes chimeric antigen receptors for expression in a Natural Killer (NK) cell, pharmaceutical compositions that include NK cells (and/or iPSCs) modified to express a chimeric antigen receptor, and methods involving such chimeric antigen receptors. Generally, the chimeric antigen receptor includes an ectodomain that includes an antigen recognition region, a transmembrane domain linked to the ectodomain, and an endodomain linked to the transmembrane domain. The endodomain can include a signaling peptide that activates an NK cell.

CROSS-REFERENCE TO RELATED APPLICATION

This application is the § 371 U.S. National Stage of InternationalApplication No. PCT/US2016/015351, filed 28 Jan. 2016, which claimspriority to U.S. Provisional Patent Application Ser. No. 62/109,281,filed Jan. 29, 2015, each of which is incorporated herein by reference.

SUMMARY

This disclosure describes, in one aspect, a chimeric antigen receptorfor expression in a Natural Killer (NK) cell. Generally, the chimericantigen receptor includes an ectodomain that includes an antigenrecognition region, a transmembrane domain linked to the ectodomain, andan endodomain linked to the transmembrane domain. The endodomain caninclude a signaling peptide that activates an NK cell.

In some embodiments, the antigen recognition domain can specificallybind an antigen associated with a disease.

In some embodiments, the antigen recognition domain can specificallybind a tumor antigen.

In some embodiments, the ectodomain can further include a signal peptideor leader sequence and/or a spacer.

In some embodiments, the endodomain can include a signaling domain ofand NK cell membrane-bound signaling adaptor protein such as, forexample, 2B4, DAP10, DAP12, IL21R, CD137 (41BB), or CD3ζ.

In some embodiments, the transmembrane domain can include atransmembrane region of a natural cytotoxicity receptor expressed in NKcells such as, for example, CD16, NKp44, NKp46, or NKG2D.

In another aspect, this disclosure describes a pharmaceuticalcomposition that includes an NK cell (and/or iPSCs) modified to expressany embodiment of chimeric antigen receptor summarized above.

In another aspect, this disclosure describes a method of providingimmunotherapy to a subject having a condition. Generally, the methodincludes administering to the subject the therapeutic compositionsummarized above in which the antigen recognition region of the chimericantigen receptor specifically binds to an antigen associated with thecondition.

The above summary is not intended to describe each disclosed embodimentor every implementation of the present invention. The description thatfollows more particularly exemplifies illustrative embodiments. Inseveral places throughout the application, guidance is provided throughlists of examples, which examples can be used in various combinations.In each instance, the recited list serves only as a representative groupand should not be interpreted as an exclusive list.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. (A) Exemplary natural cytotoxicity receptors and the effect ofbinding those receptors with their ligands on NK cell degranulation andpolarization and target cell killing. (B) Representative examples ofnatural cytotoxicity receptors and their corresponding signalingadaptors. (C) Third generation chimeric T cell antigen receptorconstruct used in iPSC-derived NK cells.

FIG. 2. (A) A generalized schematic illustration of an NK-activatingCAR. (B) Schematic of novel chimeric antigen receptor constructs.Chimeric antigen receptors were cloned into a pkt2 vector containing anIR/DR for use with SB100X transposase, a mCAGs promoter, chimericantigen receptor (CAR) sequence, Internal ribosomal entry site (IRES),and GFP:Zeo selection marker. Chimeric antigen receptor fragments wereobtained from UniProt and assembled through gBlock synthesis andtraditional restriction enzyme cloning (IDT).

FIG. 3. Surface expression of chimeric antigen receptors in NK92 and iPScells. NK92 cells or iPS cells were transfected using the SleepingBeauty transposon system using SB100X. Cells were then selected usingZeocin and flow cytometry was performed to assess cell surfaceexpression of the various chimeric antigen receptors. Expression wasassessed using a biotin-conjugated polyclonal goat anti-mouse antibodyrecognizing the mouse IgG F(ab′)2 fragment (Jackson ImmunoResearchLaboratories, Inc., West Grove, Pa., cat #115-065-072). Bound antibodywas detected using strepavadin conjugated to a fluorescent dye.

FIG. 4. CD107A release and IFN-γ production in NK92 Cells. NK92 celldegranulation and cytokine production were evaluated by flow cytometry.NK92 cells were mixed 1:1 with mesothelin negative (MA148), mesothelinpositive (A1847) ovarian cancer target cells, or Protein A beads with orwithout conjugation to a mesothelin/Fc chimeric protein. Cells werestained for CD107a and intracellular staining was performed for IFN-γproduction.

FIG. 5. Cr-51 release assay using NK92 cells. NK92, NK92/28/41BB/CD3, orNK92/CAR4 cells were incubated for 4 hours at the indicated ratios withK562, K562 mesothelin+, MA148, or A1847 cells. Cr-51 release was thendetected to evaluate cell killing. This experiment performed as in Wollet al., 2009, Blood 113(24):6094-6101, except that iPSC-derived NK cellswere used in place of hESC-derived NK cells.

FIG. 6. Exemplary additional NK-activating chimeric antigen receptors.

FIG. 7. Schematic illustration comparing a 3^(rd) Generation T cell CARwith exemplary NK CAR constructs reflected in FIG. 2.

FIG. 8. Schematic illustration of exemplary NK CAR constructs.

FIG. 9. Schematic illustration of exemplary NK CAR constructs.

FIG. 10. Data showing cytotoxicity of NK CARs against K562 cells

FIG. 11. Data showing cytotoxicity of NK CARs against two ovarian cancercell lines.

FIG. 12. Data showing expression of an exemplary NK CAR by inducedpluripotent stem cells.

FIG. 13. Data showing surface expression of an exemplary CAR byiPSC-derived NK cells expressing.

FIG. 14. An exemplary generalized NK CAR vector construct.

FIG. 15. An exemplary generalized NK CAR vector construct. Tandem cHS4insulators can inhibit silencing of the CAR vector and, therefore,improve expression of the CAR in NK cells and iPSCs.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

This disclosure describes chimeric antigen receptors designed tospecifically incorporate NK cell activation domains. Chimeric antigenreceptors can incorporate intracellular and/or transmembrane regionsincluding, for example, intracellular and/or transmembrane regions fromCD16, NKp44, NKp46, and/or NKG2D, linked to co-activation or signalingdomains from, for example, 2B4 (CD244), CD137 (41BB), IL21, DAP10,DAP12, and/or CD3ζ.

Chimeric antigen receptors (CARs) are engineered artificial receptorsthat can provide an engineered specificity to an immune cell thatexpresses the CAR. Generally, an immune cell population can be collectedfrom a subject that has a particular form of cancer. The collectedimmune cells can be modified to express a chimeric antigen receptor thatspecifically binds to antigens expressed by tumor cells, thenreintroduced into the subject. The modified immune cells that expressthe chimeric antigen receptor are better able to recognize and killtumor cells that express the antigen(s) specifically recognized by thechimeric antigen receptor.

Chimeric antigen receptors have been designed to activate T cells forthe treatment of refractory ALL (targeting CD19), pancreatic cancer(targeting mesothelin), and other malignancies. Several chimeric antigenreceptors constructs exist, but most were designed to activate T cells.

In contrast, the chimeric antigen receptors described herein aredesigned to be expressed in induced pluripotent stem cells (iPSCs),which can then be differentiated into NK cells. They also can beexpressed directly into peripheral blood (PB)-NK cells, NK-92 cells, oranother suitable NK cell line. NK-92 cells or other NK cell lines havebeen used in clinical studies for anti-cancer therapy. NK cells thatexpress the chimeric antigen receptor can then be used as animmunotherapy for the treatment of multiple cancers. The chimericantigen receptors described herein can include a signaling domain thatcould be used with antigen-recognition portions of various targetingantibodies. Specifically, this disclosure describes exemplaryembodiments that reflect mesothelin-targeted chimeric antigen receptorsfor the treatment of ovarian cancer. The described embodiments can havebroader utility, however, since mesothelin is expressed on manyadenocarcinomas. Moreover, the described mesothelin targeting domain ismerely exemplary; other single chain variable fragments (scFVs) can beengineered into the NK-specific chimeric antigen receptor (NK-CAR)signaling constructs to target essentially any malignancy.

One feature of the NK cell chimeric antigen receptors described hereinis that one can bypass the adaptor molecules/accessory proteins thatnatural cytotoxicity receptors need to initiate signal transduction.Alternatively, or additionally, including the transmembrane domain ofreceptors that typically associate with an adaptor molecule/accessoryprotein can allow accessory proteins to bind as well, making signaltransduction more likely to be initiated. The NK cell chimeric antigenreceptors designed to include, for example, CD3ζ can allow bypassingother natural cytotoxicity receptors. Incorporating the transmembranedomains and other intracellular domains can allow these NK cell chimericantigen receptors to associate with adaptor proteins and provideimproved signaling over CD3ζ alone through activation of multiplepathways.

While some T cell chimeric antigen receptor constructs can activate NKcells to some degree due to shared signaling domains, the chimericantigen receptors described herein are specifically designed to activateNK cells. Chimeric antigen receptors designed to specifically activateNK cells can improve NK function and receptor utility in NK cellimmunotherapy such as, for example, cell-mediated killing of refractorytumors.

A chimeric antigen receptor typically includes an ectodomain, atransmembrane domain, and an endodomain. The endodomain typicallyresides in the cytoplasm of the cell. Once an antigen is recognized bythe ectodomain, the endodomain transmits an activation signal to the NKcell that induces the NK cell to destroy the targeted tumor cell.Exemplary signaling endodomains include, for example, the signalingdomains of membrane-bound signaling adaptor proteins, including, forexample, 2B4 (CD244), CD137 (41BB), IL21, DAP10, DAP12, and/or CD3ζ, ora portion thereof including, for example, an immunoreceptortyrosine-based activation motif (ITAMs), a YxxM motif, a TxYxxV/I motif,FcRγ, NKp80 (signaling through an atypical hemi-ITAM), and/or DNAM, etc.

The transmembrane domain traverses the plasma membrane and links theendodomain to the ectodomain. Exemplary transmembrane domains include,for example, the intracellular and/or transmembrane domains of naturalcytotoxicity receptors (NCRs) including for example, CD16, NKp44, NKp46,NKG2D, NKp30, NKp80, and/or DNAM-1, or a portions thereof including, forexample, one or more charged amino acids. In some embodiments, thecharged amino acid can be a lysine and/or an arginine residue. In somecases, a transmembrane region may be from a transmembrane protein,meaning that it natively has an extracellular C-terminal rather than anextracellular N-terminal. In such cases, one can reverse the orientationof the transmembrane region, indicated in, for example, FIG. 6 as “RevTM” so that the chimeric antigen receptor orients properly in the NKcell membrane.

The ectodomain generally includes a signal peptide and an antigenrecognition region. In many embodiments, the ectodomain also can includea spacer. The signal peptide directs the nascent polypeptide into theendoplasmic reticulum so that it can be properly glycosylated andanchored into the plasma membrane. Generally, any eukaryotic signalpeptide can be used so long as it directs the protein to the endoplasmicreticulum. One exemplary signal peptide includes the CD8α leadersequence, but other signal peptide sequences may be suitable. Thespacer, when present, links the antigen recognition domain to thetransmembrane domain. The spacer typically offers flexibility so thatantigen recognition region is free to orient in different directions,thereby allowing the antigen recognition region to bind to antigentargets. One exemplary spacer includes the CD8α hinge sequence, butother Ig hinge regions may be suitable. The antigen recognition regioncan include any peptide sequence that is capable of specifically bindingto a designated target. As used herein, “specifically bind” andvariations thereof refer to having a differential or a non-generalaffinity, to any degree, for a particular target. Thus, the antigenrecognition region can include a fragment of an antibody such as, forexample, an scFv or a Fab that specifically binds to a particularantigen such as, for example, a tumor antigen, a viral antigen, amodified self-antigen, etc. In some embodiments, the scFv can be from amonoclonal antibody. A chimeric antigen receptor can be designed toinclude an antigen recognition region that can specifically bind to anydesignated target. Thus, while FIG. 2, FIG. 6, FIG. 7, and FIG. 8 showembodiments that are designed to specifically bind to mesothelin, anNK-activating chimeric antigen receptor can be designed to specificallybind, and therefore target, any antigen associated with cells that areintended to be the target of NK cell-mediated killing including, forexample, tumorigenic or virally infected cells. For example, NK cellsand/or CARs have demonstrated activity against diverse solid tumors andvirally-infected cells including but limited to HIV (humanimmunodeficiency virus), hepatitis B, hepatitis C, CMV(cytomegalovirus), EBV (Epstein-Barr virus), HPV (human papillomavirus), and others.

So, for example, to better mediate NK cell cytotoxicity against tumorsthat include cells that express mesothelin (e.g., ovarian cancers,pancreatic cancers, lung cancers, colon adenocarcinomas, mesotheliomas,and other adenocarcinomas that express mesothelin), a chimeric antigenreceptor such as ones shown in FIG. 2, FIG. 6, FIG. 7, and FIG. 8 may bedesigned and expressed in NK cells. The illustrated chimeric antigenreceptor constructs contain an NK cell-specific transmembrane domain andactivating domains, and was capable of being expressed in the NK celltumor line, NK92. Transmembrane and intracellular regions were takenfrom CD16, NKp44, NKp46, and/or NKG2D, while the activating domains of2B4, DAP10, DAP12, and/or CD3ζ were combined in a fashion intended tomaximally activate NK cells. FIG. 3 shows that NK92 and iPS cellsexpressed the chimeric antigen receptors shown in FIG. 2.

To assess the function of the chimeric antigen receptors, NK cellsexpressing the chimeric antigen receptors were tested againstantigen-coated beads and mesothelin-expressing cell lines. FIG. 4 showsthat the chimeric antigen receptors of FIG. 2 enhanced degranulation andcytokine production of NK cells when NK cells expressing the chimericantigen receptors were mixed with mesothelin-positive targets.

FIG. 5 shows that NK92 cells expressing an NK-specific chimeric antigenreceptor as described herein improved in vitro killing ofmesothelin-positive target cells compared to a third generation Tcell-specific chimeric antigen receptor (NK92/28/41BB/CD3ζ) ornon-transfected NK92 cells.

FIG. 9 shows cytotoxicity of exemplary NK CARs against K562 cells (upperleft panel) and K562 cells expressing mesothelin (upper right panel)that is target for the CARs. These results show markedly improvedkilling in a mesothelin-specific fashion, most notably for CAR7 andCAR9. The lower panel is a summary of the results expressed in lyticunits (Bryant et al., 1992, J Immunol Methods 146(1):91-103). CAR 7 andCAR 9 exhibit markedly greater cytotoxicity than the 3^(rd) generation Tcell CAR used in previous studies (NK92 meso 3^(rd)). Cytotoxicity wasmeasured using a Cr-51 release assay as previously described (Knorr etal., 2013, Stem Cells Transl Med 2(4):274-283; Woll et al., 2009, Blood113(24):3094-6101; Woll et al., 2005, J Immunol 175(8):5095-5103). FIG.10 shows similar results using two ovarian cancer cell lines that aremeso-high (A1497) and meso-low (MA148). NK92 cells with different NKcell-based anti-meso CARs kill in a meso-specific fashion. The bottompanel against reflects a summary expressed in lytic units. Moreover, theNK CARs mediate increased expression of CD107a and/or IFN-γ whenstimulated with targets as in FIG. 9 and FIG. 10 (data not shown).

In some embodiments, an NK-specific chimeric antigen receptor asdescribed herein can be expressed in iPSCs, which can then bedifferentiated into NK cells. The iPSCs may be differentiated asdescribed in Knorr et al., 2013, Stem Cells Transl Med. 2(4):274-283 orNi et al., 2014, Stem Cells 32(4):1021-1031. FIG. 11 shows expression ofan exemplary NK CAR by induced pluripotent stem cells (iPSCs), as shownby production of CD45+CD56+ cells (top row, 5^(th) panel). FIG. 12 showsCAR surface expression by iPSC-derived NK cells. The bottom three rowsof FIG. 12 show CAR expression only on the surface of iPSC-CAR4v2(4^(th) column, bottom three rows) compared to the PB-NK cells andiPSC-NK cells that don't express CARs (unmodified control cells, 4^(th)column, row 4 and row 5). Other panels in FIG. 11 and FIG. 12 show othertypical NK cell surface antigens/receptors on the iPSC-CAR4v2 aresimilar to those found on the unmodified control cells. These resultsindicate that iPSC-derived NK cells can exhibit the same target-specificcytotoxicity as the mesothelin-targeted-CAR-expressing NK cells in FIG.9 and FIG. 10.

A polynucleotide that encodes an NK CAR construct may be introduced intoan NK cell or iPSC using conventional transfection method. Thus, whiledescribed herein in the context of an exemplary embodiment in which apolynucleotide encoding the CAR is transfected into cells using aSleeping Beauty transposon system, NK cells (and/or iPSCs) may bemodified using any suitable transfection method. FIG. 14 illustrates anexemplary vector construct that may be used to modify NK cells (and/oriPSCs) to express a chimeric antigen receptor. FIG. 15 illustrates theconstruction of an alternative exemplary vector that further includestandem cHS4 insulators (Aker et al., 2007, Hum Gene Ther 18(4):333-343),which can inhibit silencing of the CAR vector and, therefore, improveexpression of the CAR in NK cells and iPSCs.

NK cells and/or iPSCs modified to express a chimeric antigen receptordescribed herein may be formulated into a pharmaceutical compositionalong with a “carrier” for delivery to a subject having a condition atleast partially characterized by cells that can be targets of NKcytotoxicity. As used herein, “carrier” includes any solvent, dispersionmedium, vehicle, coating, diluent, antibacterial, and/or antifungalagent, isotonic agent, absorption delaying agent, buffer, carriersolution, suspension, colloid, and the like. The use of such mediaand/or agents for pharmaceutical active substances is well known in theart. Except insofar as any conventional media or agent is incompatiblewith the active ingredient, its use in the therapeutic compositions iscontemplated. Supplementary active ingredients also can be incorporatedinto the compositions.

By “pharmaceutically acceptable” is meant a material that is notbiologically or otherwise undesirable, i.e., the material may beadministered to an individual along with NK cells (and/or iPSCs)modified to express a chimeric antigen receptor without causing anyundesirable biological effects or interacting in a deleterious mannerwith any of the other components of the pharmaceutical composition inwhich it is contained.

The pharmaceutical composition may be formulated in a variety of formsadapted to a preferred route of administration. Thus, a composition canbe administered via known routes including, for example, parenteral(e.g., intradermal, transcutaneous, subcutaneous, intramuscular,intravenous, intraperitoneal, etc.) or topical (e.g., intratracheal,intrapulmonary, etc.). A composition also can be administered via asustained or delayed release.

A formulation may be conveniently presented in unit dosage form and maybe prepared by methods well known in the art of pharmacy. Methods ofpreparing a composition with a pharmaceutically acceptable carrierinclude the step of bringing NK cells (and/or iPSCs) modified to expressa chimeric antigen receptor into association with a carrier thatconstitutes one or more accessory ingredients. In general, a formulationmay be prepared by uniformly and/or intimately bringing the NK cells(and/or iPSCs) into association with, for example, a liquid carrier.

A pharmaceutical composition that includes NK cells (and/or iPSCs)modified to express a chimeric antigen receptor may be provided in anysuitable form including but not limited to a solution, a suspension, anemulsion, a spray, an aerosol, or any form of mixture. The compositionmay be delivered in formulation with any pharmaceutically acceptableexcipient, carrier, or vehicle.

The amount of NK cells (and/or iPSCs) modified to express a chimericantigen receptor that is administered to a subject can vary depending onvarious factors including, but not limited to, the weight, physicalcondition, and/or age of the subject, whether one or more chimericantigen receptors are being administered, and/or the route ofadministration. Thus, the absolute amount of NK cells (and/or iPSCs)included in a given unit dosage form can vary widely, and depends uponfactors such as the species, age, weight and physical condition of thesubject, as well as the method of administration. Accordingly, it is notpractical to set forth generally the amount that constitutes an amountof NK cells (and/or iPSCs) modified to express a chimeric antigenreceptor that is effective for each and/or all possible applications.Those of ordinary skill in the art, however, can readily determine theappropriate amount with due consideration of such factors.

In some embodiments, the method can include administering a sufficientnumber of NK cells (and/or iPSCs) modified to express a chimeric antigenreceptor to provide a dose of, for example, from about 10⁵ cells/kg toabout 10¹⁰ cells/kg to the subject, although in some embodiments themethods may be performed by administering an amount of NK cells (and/oriPSCs) in a dose outside this range. In some of these embodiments, themethod includes administering sufficient NK cells (and/or iPSCs)modified to express a chimeric antigen receptor to provide a dose offrom about 10⁷ cells/kg to about 10⁸ cells/kg to the subject, forexample, a dose of from about 1×10⁷ cells/kg to about 8×10⁷ cells/kg.

Alternatively, the dose may be calculated using actual body weightobtained just prior to the beginning of a treatment course. For thedosages calculated in this way, body surface area (m²) is calculatedprior to the beginning of the treatment course using the Dubois method:m²=(wt kg^(0.425)×height cm^(0.725))×0.007184.

In some embodiments, the pharmaceutical composition that includes NKcells (and/or iPSCs) modified to express a chimeric antigen receptor maybe administered, for example, from a single dose to multiple doses perweek, although in some embodiments the method can be performed byadministering the pharmaceutical composition at a frequency outside thisrange. In certain embodiments, the pharmaceutical composition may beadministered from about once per month to about five times per week.

Generally, the pharmaceutical composition is administered to a subjectin an amount, and in a dosing regimen effective to reduce, limit theprogression of, ameliorate, or resolve, to any extent, the symptoms orclinical signs of the condition. As used herein, “ameliorate” refers toany reduction in the extent, severity, frequency, and/or likelihood of asymptom or clinical sign characteristic of a particular condition.“Symptom” refers to any subjective evidence of disease or of a patient'scondition. “Sign” or “clinical sign” refers to an objective physicalfinding relating to a particular condition capable of being found by oneother than the patient.

In the preceding description, particular embodiments may be described inisolation for clarity. Unless otherwise expressly specified that thefeatures of a particular embodiment are incompatible with the featuresof another embodiment, certain embodiments can include a combination ofcompatible features described herein in connection with one or moreembodiments.

For any method disclosed herein that includes discrete steps, the stepsmay be conducted in any feasible order. And, as appropriate, anycombination of two or more steps may be conducted simultaneously.

The present invention is illustrated by the exemplary embodimentsdescribed above. It is to be understood that the particular examples,materials, amounts, and procedures are to be interpreted broadly inaccordance with the scope and spirit of the invention as set forthherein.

As used herein, the term “and/or” means one or all of the listedelements or a combination of any two or more of the listed elements; theterms “comprises” and variations thereof do not have a limiting meaningwhere these terms appear in the description and claims; unless otherwisespecified, “a,” “an,” “the,” and “at least one” are used interchangeablyand mean one or more than one; and the recitations of numerical rangesby endpoints include all numbers subsumed within that range (e.g., 1 to5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

The complete disclosure of all patents, patent applications, andpublications, and electronically available material (including, forinstance, nucleotide sequence submissions in, e.g., GenBank and RefSeq,and amino acid sequence submissions in, e.g., SwissProt, PIR, PRF, PDB,and translations from annotated coding regions in GenBank and RefSeq)cited herein are incorporated by reference in their entirety. In theevent that any inconsistency exists between the disclosure of thepresent application and the disclosure(s) of any document incorporatedherein by reference, the disclosure of the present application shallgovern. The foregoing detailed description and examples have been givenfor clarity of understanding only. No unnecessary limitations are to beunderstood therefrom. The invention is not limited to the exact detailsshown and described, for variations obvious to one skilled in the artwill be included within the invention defined by the claims.

Unless otherwise indicated, all numbers expressing quantities ofcomponents, molecular weights, and so forth used in the specificationand claims are to be understood as being modified in all instances bythe term “about.” Accordingly, unless otherwise indicated to thecontrary, the numerical parameters set forth in the specification andclaims are approximations that may vary depending upon the desiredproperties sought to be obtained by the present invention. At the veryleast, and not as an attempt to limit the doctrine of equivalents to thescope of the claims, each numerical parameter should at least beconstrued in light of the number of reported significant digits and byapplying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. All numerical values, however, inherently contain a rangenecessarily resulting from the standard deviation found in theirrespective testing measurements.

All headings are for the convenience of the reader and should not beused to limit the meaning of the text that follows the heading, unlessso specified.

What is claimed is:
 1. A chimeric antigen receptor molecule comprising,in an N-terminus to C-terminus orientation: an ectodomain comprising anantigen recognition region; a hinge; a transmembrane domain comprising atransmembrane region of NKG2D (cluster of differentiation 314 or CD314)in reverse orientation as compared to native NKG2D that natively has anextracellular C-terminus; and an endodomain comprising a functionalsignaling domain that activates a Natural Killer (NK) cell, wherein saidfunctional signaling domain is selected from the group consisting of:(a) a 2B4 (cluster of differentiation 244 or CD244) intracellular domain(ICD) and a CD3 zeta (CD3ζ) signaling domain; (b) a 41BB (cluster ofdifferentiation 137 or CD137) ICD and a CD3ζ signaling domain; (c) aDAP12 (DNAX activation protein of 12 kDa) ICD and a CD3ζ signalingdomain; (d) a 2B4 ICD, a 41BB ICD and a CD3ζ signaling domain; (e) aIL21R ICD and a CD3ζ signaling domain; and (f) a 41BB ICD, a 2B4 ICD anda CD3ζ signaling domain.
 2. The chimeric antigen receptor of claim 1wherein the antigen recognition domain specifically binds an antigenassociated with a disease.
 3. The chimeric antigen receptor of claim 1wherein the antigen recognition domain specifically binds a tumorantigen.
 4. The chimeric antigen receptor of claim 1 wherein theectodomain further comprises a signal peptide or leader sequence.
 5. Thechimeric antigen receptor of claim 1, wherein said hinge is a CD8αhinge.
 6. A pharmaceutical composition comprising an NK cell thatexpresses the chimeric antigen receptor of claim
 5. 7. Thepharmaceutical composition of claim 6, wherein the NK cell is derivedfrom an iPSC.